1. Field of the Invention
The present invention relates to a belt connecting device attached at ends of belts such as belt, cord or the like, for connecting these ends with each other. The belts shall be called simply xe2x80x9cbeltxe2x80x9d in the specification.
2. Description of the Related Art
Conventionally, various engagement and disengagement structures for this kind of belt connecting device have been disclosed in, for example, Japanese Utility Model Publication Nos. 62-36814, 5-35699, and 7-95, Japanese Utility Model Laid-open Publication No. 7-34706 and the like.
In these proposals, an engaging/disengaging portion of any male engaging/disengaging member has a disk shape flange around an axial line of a post protrusion projecting from one surface of a plate shaped member at the tip of the post protrusion, and this engaging/disengaging portion engages with and disengages from an engaged/disengaged portion of a female member. The engaged/disengaged portion is formed on a tongue piece extending from a body of the female member, is composed of a part of a long hole opening at one end of the tongue piece and has a structure for guiding in slide contact side faces of the post protrusion of the male engaging/disengaging member and for engaging a rear face of the flange by contact with the engaged face of the surface thereof.
Therefore, the engagement operation of the male member and the female member is performed by inserting a protrusion section of the male member from an open insertion slot of the long hole of the female member, in a way to approach both ends of a belt each other, and thereafter, by pulling both belt ends in the separation direction to engage with each other. And the disengagement operation thereof is performed by pulling out the protrusion section of the male member from the long open insertion slot of the female member, in a way to approach both ends of the belt each other.
Thus, in the engagement and disengagement operation of the aforementioned belt connecting device, a relative displacement operation of the male member and the female member in a way to pulling or approaching the belt ends toward each other along the belt connection direction in both cases must be performed intentionally, thereby making the engagement and disengagement operation complicated.
In addition, for example, when the male member and the female member are in engagement, the mutual engagement tends to be released easily when the belt is slack, and can not be disengaged easily in a case when the belt can not be loosened in a state where the belt is stretched.
The present invention is devised to solve such conventional problems and an object of the invention is to provide a belt connecting device facilitating the engagement and disengagement operation of a male member and a female member and not only facilitating the disengagement even when the belt is stretched, but also preventing easy disengagement when the belt is slack.
A main aspect of the present invention provides a belt connecting device composed of a female member and a male member which can engage with and disengage from each other, and the female member has an annular body and has a belt connecting portion at one end thereof and an engaged/disengaged portion for engaging with and disengaging from the male member at the middle of the other end thereof, while the male member has a plate shaped body and has a belt connecting portion at one end thereof and has an engaging/disengaging portion for engaging with and disengaging from the engaged/disengaged portion of the female member at a middle portion thereof. The engaged/disengaged portion of the female member is composed of a substantially U-shaped pinching resilient portion open at the belt connecting portion and extending substantially on one plane from the other end. The engaging/disengaging portion of the male member includes a protruded portion projecting substantially from a rear side middle portion of the plate shaped body and at least the end face portion of the belt connecting portion side having a configuration to be circumscribed by a pinching surface of the pinching resilient portion of the female member, and a substantially C-shaped attachment flange a rear face of which engages with a surface attachment face of the pinching resilient portion at an upper end of the protruded portion. And the attachment flange has a projection amount gradually increasing from the protruded section in a direction toward the belt connecting portion of the male member.
In this invention, the protruded portion to be formed on the engaging/disengaging portion of the male member has the configuration to be circumscribed by the pinching face of the pinching resilient portion of the female member and the projection amount of the attachment flange to be formed at the top end of the protruded portion from the protruded portion is increased gradually in a direction toward the belt connecting portion of the male member. Therefore, when the female member and the male member are to be engaged, the end face portion of the belt connecting device side of the protruded portion is fitted to the pinching face of the pinching resilient portion, and at the same time, the attachment flange attaches with the surface attachment face of the pinching resilient portion to be engaged firmly.
Also, when the female member and the male member are to be disengaged, both members can be disengaged easily by rotating so as to lift an end opposite to the belt connecting side of the female member with fingers, allowing to move in a way to disengage gradually from the attachment face of the pinching resilient portion from the flange portion with small protrusion amount of the attachment flange to the flange portion with large protrusion amount.
Preferably, the pinching resilient portion has a guide space for guiding the engaging/disengaging portion, enlarged gradually toward the belt connecting portion side, and an arc shaped pinching space adjacent to the guide space. The structure of such pinching resilient portion ensures a smooth insertion and extraction operation of the engaging/disengaging portion of the male member in respect to the pinching resilient portion of the female member, for engaging with and disengaging from the male member. Moreover, in combination with the foregoing features of the invention of the main aspect, it is possible to perform the engagement/disengagement securely and easily.
Further preferably, the protruded portion of the male member has a substantially U-shape opening toward an end opposite to the belt connecting portion in a plan view, an end at the side of the belt connecting portion has an arc shape outer surface fitting with the pinching space, and a projection height of legs extending to a side away from the belt connecting portion at least at a connecting portion with the flange has the same height as a top face of the flange.
A dimension between outer sides of the pair of right and left legs are set approximately equal to the right and left width dimension of a connection area between the guide space and the pinching space of the aforementioned pinching resilient portion. Since the protruded portion is not a simple column but has a leg outside face adjacent to a cylindrical outer surface, when the female member and the male member are engaged, both members do not rotate relatively around the protruded portion, allowing to perform smoothly the insertion and extraction operation of the male engaging/disengaging portion in respect to the pinching resilient portion.
Preferably, a pair of respective resilient legs extending to the belt connecting portion side of the pinching resilient portion have long holes extending longitudinally in middle portions thereof. The formation of the long holes ensures the strength of the resilient legs and facilitates the elastic deformation in the right and left direction, making it easy to engage/disengage the female member with/from the male member.
Further preferably, top faces of the resilient legs have a plane extending in parallel to a rear side of the annular body toward the belt connecting portion, and a taper face inclined downward toward a tip end adjacent to the plane.
With such structure, if the end of the male member at the side opposite to the belt connecting portion is rotated in a direction for separating the male member from the female member around the end of the belt connecting portion side, the attachment flange of the male engaging/disengaging portion inclines relatively in respect to the female member, the flange portion of a belt fixing rod side where the projection amount is maximum moves in a direction away from the arc shape pinching face of the pinching resilient portion of the female member and moves, being guided consecutively along the taper face formed on the top face of the resilient leg of the female member, from the flange portion of the right and left leg side with the minimum projection amount to the flange portion with the maximum projection amount.
The guide space of the insertion/extraction slot area where this taper face is set larger than the maximum right and left width of the attachment flange, the attachment flange shifts consecutively to the guide space from a portion where the projection amount is small to a portion where the projection amount is large, thereby disengaging automatically the female member and the male member.
Consequently, according to the present invention, when the female member and the male member are to be disengaged, it is unnecessary to move the female member and the male member intentionally to approach each other, and they can be disengaged simply by performing the rotation operation in the direction to separate one end of the male member from the female member taking the belt connecting portion as fulcrum.
Preferably, the thickness of a part of the belt connecting portion of the male member or female member is increased to an engaging/disengaging face side substantially by an entire thickness of the mating member. When both members engage in a superposed state, no step will be generated in the whole, and the appearance will be attractive, by making the belt connecting portion side end of one of the male member or the female member locally have a predetermined thickness, as mentioned above.